Inspiron 1501 with firewire expresscard fault

Hi, my first ever post here

I bought a Dell Inspiron 1501 (dual core Turion 64 version) this year and later bought a Belkin firewire (with TI chip) expresscard as there is no firewire port on the laptop.

I now find that using the card to connect to an external drive fails both in Vista and Ubuntu. Either OS will detect the drive okay, but then complain of an I/O error when I try to do anything (ie read/write files) with it (sorry don't have details to hand). The drive worked fine with my (ancient) Vaio. (btw, controller in drive is a Prolific chip)

I read on the thread concerning 1501's with Intel core duo cpu's that there was a problem with expresscard firewire souncards - someone thought it might be a latency issue. Started new thread as other thread is Intel specific.

I'm now trying to establish whether I've bought a duff expresscard or if the problem is with the Dell/expresscard/firewire combination. I think this is more likely because:
The usb port on the expresscard works fine
Other people have had issues with a similar combination
Dell have not implemented ACPI hotplug support for expresscards correctly (this only becomes an issue if you use Linux) - so I wonder what else they've got wrong.

Although I can use usb for this, I really want to stick with firewire.

Thoughts/suggestions anyone?

TIA, Alexis